Steam trap



F. BASENAU' STEAM TRAP Filed July 18, 1925 Aug. 16,1927.

3 Sheets-Sheet 1 g d d 76in d: V a; J/zwgziar Aug. 16, 1927.

, F. BASENAU STEAM TRAP Filed July 18, 1923 3 Sheets-Sheet 3 War/16y I iii/imam- Patented Aug. 16, 1927. v

UNITED, STA

FRED E B-IK BASENAU, OF AMSTERDAM, JQETHERLANDS.

s'rnA /r range.

Application filed July 18, 1923, Serial' No. 652,284, and in Germany July 21, 1922.

This invention relates to steam traps or devices for discharging water of condensation from steam pipes or heating systems and relates more particularly to steam traps sively increasing resistance to the flow of a mixture of steam and water as the wetness of the mixture increases so that in time as the pressure difference pushingthe mixture through the orifice falls, the liquid, water, is not pushed through but settles as a globule of water in the orifice where itperforms the function of avalve. The orifice thus, under these conditions, provides a free passage for water but is an effective bar to the passage of steam so long as the pressure difference of the fluid on opposite sides of the nozzle is within the limit of the back pressure set up by the resistance ofthe nozzle to the passage of water. It now the resistance of the nozzle in such a case is so designed that it is equal to thedesired normal or maximum pressure difference it is sought tov maintain between the inlet pressure to the steam trap and the outlet or discharge pressure, the nozzle will not only perform the function of an effective steam trap but will also act as an automatic relief valve. The reason of this is that when an excess pressure v diflerence occurs, the globule of water in the nozzle will be blown out and vapour will escape until the pressure difference again becomes less than the back pressure setup by the resistance of the nozzle to the passage of water.

I have-found that the best results are obtained by forming the continuously open orifice as a conical nozzle converging in the direction of flowbt the fluid through the trap" and having the sides formed as part of a cone with an angle of at its apex, that'is, in section the sides will make an angle of 325 with the axis. The size of'the free openin at its most constricted point depends upon.t e probable rate of condensation and must be adequate to drain the conduit or heating system at tull load, but the ratio of the wide'to' the constricted part'of the nozzle is in the neighbourhood of l/6th as measured by the diameters, that is to say 1/36th as measured by areas.

My invention thus consists of a steam trap hav ng a casing or body par-t provided with an inlet and a discharge for water of con densation and a continuously open conical nozzle interposedas a resistance in the path of flow of the fluid through the trap so that the nozzle converges in the direction of flow with its sides at an angle of 65.

The invention also embodies the organization of this nozzle orifice with a valve and a sieve so that the trap may be blowirofl in such a manner as to remove impurities intercepted by the sieve.

In order that my invention may be more clearly understood several examples embodying the same havebeen shown in the accompan-ying drawings. In said drawings,

Fig. 1, is an elevation showing the nozzle,

Fig. 2, is a vertical longitudinal section thereof, i I i Fig. 3, is avertical longitudinal section showing a steam trap provided with my improved nozzle, a

Fig. 4, is a similar section showing a modification,

Fig. 5, is a horizontal'section taken on the line 5-5 of Fig. 4,

Fig. 6, is a sectional elevation showing another modification, and i Fig. 7, is a horizontal section taken on the line 77 ofFig'. 6.

In the example shown in Figs. :1 and 2 my 7 improved nozzle a is in the form of an externally screw-threaded plug having an axial bore or passage comprising a cylin-' drical portion '6 and an outwardly tapering'or conical portionl) located at the discharge end of the nozzle. The solid angle at the apex o'f the conical portion is 1 5, the angle of the conical wall to the axis being 32.5.which value has been entered in Figs. land 2. The discharge ends of the portion Z2 is in the form of a sharp annular edge 0. I

Such a nozzle forms a resistance in the direction of flow of the fluid, the resistance being greatest at the most constricted part. The amountof this resistance for any given nozzle will vary with the nature or specific gravity of the fluid and will be greater for water than torvapour. If new the resist= ance to water How is substantially equal or greater than the pressure fall which is required to cause a steam flow through the orifice, water of condensation will pass but steam will be retained owing to the fact that it cannot force the water through the orifice at the generally prevailing pressure differences on each side of the orifice. I find that these conditions are most nearly attained in practice by the form described and shown in the drawings.

In Fig. 3 I have shown my improved nozzle as mounted in a casing cl provided with a flange (1 for connecting the same to a steam pipe or the like for removing therefrom the condensed water. The casing is divided by a partition wall (Z into two chambers or passages (Z and d and the chamber (Z contains a sieve c separating the main portion from the nozzle a screwed into a bore of the partition wall d. Coaxially of the nozzle a an opening is made in the outer wall of the casing which is nor mally closed by a screw plug 7, and which permits cleaning of the nozzle. The condensed water is discharged through the nozzle (a and into the chamber (Z from whence it passes either into the open or is conducted through a pipe in the usual manner for further use. The chambers (Z and d are adapted to be connected with each other through a second passage normally closed by a hand operated blow-off valve 9, which valve may be temporarily opened for diverting any excessive quantity of condensed water from the nozzle (4 and for permitting the sieve to be cleaned. The object of the sieve is to keep foreign matter such as particles of packing material away from the nozzle a, and it is desirable from time to time to remove such foreign matter from the sieve. For this purpose, the valve 9 may be opened, thereby allowing the steam to flow at high velocity past the bottom face of the sieve and to dislodge any impurities.

The operative part of the steam trap is the nozzle the construction of which has been described in detail with reference to 1 and 2. The operation does not depend on any .movable parts which would render the action unreliable, particularly where the trap is required to be operative over long periods. 7

In the modification shown in Figs. 4 and 5 my improved nozzle a is mounted in a valve cone 72. having an axial bore 7L in line with the bore of thenozzle and transverse bores 7L2. The valve cone is disposed within a casing z' having an inlet 2' and an outlet i and adapted to be connected by flanges *2' and 2' respectively tosupply and discharge pipes for condensed water. The valve cone h isnormally forced on its seat i by a hand operated valve stem 71 carrying at its top end a hand wheel h, The valve cone h is formed with an annular shoulder h and the stem 7? is provided with a flange h. In the said shoulder and flange a cylindrical sieve is fitted, so that the condensed water has access to the nozzle a only through the sieve, which thus prevents any impurities from reaching the nozzlea. The sieve may be inspected through a lass plate L" fitted in the wall of the casing 2 at a-part opposite to the inlet 2' and fixed in position by an annular screw As appears more particularly from Fig. 5 the inlet passage 2' is curved out of radial direction and into a direction tangentially of the sieve j and the wall of the casing sur-' rounding the same, so that when valve h is opened steam admitted through the inlet passage 71 flows in the direction of the arrow I and circumferenti'ally of the sieve thus removing therefrom any foreign matter deposited thereon. When turning the stem its for unseating the valve, the sieve secured thereto is gradually turned so that the whole circumference of the sieve is exposed to the action of the jet of steam.

Fig. 5 also shows that theinner or discharge end of the inlet passage is reduced in cross-section and in the form of a nozzle, so that the velocity of the steam striking against the sieve is increased. Thereby the cleaning action is improved.

In the modification shown in Figs. 6 and 7 the nozzle a is mounted within a casing Z having an inlet Z a downwardly directed tubular portion Z a tubular portion Z hav-. ing' a cap or lido screwed thereto, and a tubular portion Z closed by a glass dish Z' and an annular cap 7/. On the tubular portion Z a sleeve n is screwed, which is con: nected at its bottom end with "a pipe 7?. Th-e sleeve is externally hexagonal in form to permit a wrench to be applied thereto. As

shown the joints are made in a manner similar to pipe joints, and the construction is particularly suitable'for low pressure steam.

The sleeve n is formed internally with a flange m---foraminated near the wall of the sleeve as shown at m 'and formed with an upwardly projecting axial tubular portion Y m having the nozzle a screwed therein. To the top face of the flange, a valve ringlaterally-in the manner-described with reference to Figs. 4 and 5.

The normal operation of the trap will be understoodwithout explanation. For cleaning the sieve g the sleeve 71 is screwed downwardly by means of a wrench. Thereby the valve m m 'is opened and steam rushes through the inlet Z against the sieve, and through the valve. In" this case the sieve is gradually turned with the sleeve 12 whilst being subjected'to the action of the steam. hen valve m m is closed, the water or steam must first pass through the sieve g before being admitted to the nozzle a.

While in describing the invention reference has been niac e to a particular example embodying the same I wish it to be understood that my invention is' not, limited to the construction shown'in the drawing, and that various changes may be made inlthe general arrangement of the apparatus and'the construction of its parts without'departingfrom the invention. i

I claim:

1. A steam trap comprising a casing, a fluid inlet thereto, a fluid discharge therefrom, and means for automatically'trapping the steam without employing a valve, comprising a resistance interposed in the path ofthe'flow of' the fluid and in the form of a continuously open hollow nozzle of cone-d form internally so as to converge in the direction of flow of the fluid, the back pressure caused by the resistance of said nozzle to the passage of liquid being greater than the normal pressure difference of the fluid between said inlet and said discharge 2. A steam trap comprising a casing, a fluid inlet thereto, a fluid discharge therefrom, and means for automatically trapping the steam and for simultaneously relieving excess pressures on their occurrence, comprising a resistance interposed in the path of flow of the fluid and in the form of a continuously open hollow nozzle of coned form internally so as to converge in the direction of flow of the fluid, the backpressure caused by the resistance of said nozzle to the passage of liquid being equal to the maximum desired pressure difference between said inlet and said discharge.

3. A steam trap comprising a casing having a fluid inlet thereto and water of condensation discharge therefrom, and means for automatically trapping the steam without employing a valve comprising a single continuously open nozzle interposed in the path of flow of thefluid and internally coned so as to converge in the direction of flow, said nozzle having its internal converging sides inclined at an angle of approximately 65 degrees, a sieve interposed in the normal path of flow in front of said noz-' zle and a valve located in an extension of said casing beyond said sieve, said valve being adapted when open to cause steam to pass across the face of said sieve remote from the nozzle .to remove impurities therefrom.

4. A steam trap comprising a casing having a fluid inletnthereto and water of condensation discharge therefrom, and means for automatically'trapping the steam without employing a valve, comprising a single continuously open nozzle interposed in the path of flow oi. the fluid and internally concd so as .to converge in thedirection flow, said .nozzle having its internal converging sides inclined at an angle of approxi mately 65 degrees, a sieve interposed in the path-of flow in front of said nozzle,a valve located in an extension of said casing beyond' said sieve, said valve being adapted when open to cause steam to pass across the face of said sieve remote fromthe nozzle to remove impurities therefrom, and ineansfor inspecting saidfsieve. a w

5. A steam trap comprising a casing having a steam inlet thereto and a discharge for Waterof condensationtherefrom,a continuously open conical nozzleinterposed in the path of the flow and converging 'in the direction of flow, said nozzle having its converging sides inclined at an angle of approximately .65 degrees, a sieve movably mounted in front of said nozzle .to intercept impurities and means for moving said sieve so that its surface remote from the nozzle is swept over by steam current to remove impurities collected thereon. 7

6. A steam trap comprising a casing having a steam inlet thereto and a discharge for water of condensation therefrom, a blow ofl valve in said casing, a continuously open conical nozzle in said valve and converging in the direction of flow of steam and water of condensation through the steam trap and a cylindrical sieve mounted on said valve and interposed in front of the continuously open nozzle. t

.7. A steam trap comprising a casing having a steam inlet thereto and a discharge for water of condensation therefrom, a blow ofl' valve rotatable in said casing, a continuously open conical nozzle mounted in said blow off valve, said nozzle converging in the direction of flow ofthe steam and water of condensat on, a cylindrical sieve mounted to rotate with said valve and surrounding the' 'widest endof said nozzle, said sieve being rection of flow of the fluid through the steam trap.

9. A steam trap, comprising a casing having a steam inlet thereto and a tubular discharge for water of condensation therefrom, a valve body in the form of a sleeve, screwing in said tubular discharge, an inner flange on said valve body for normally engaging said tubular discharge and for closing the same, a continuously open conical nozzle converging in the direction of flow of the fluid through the steam trap and located centrally on said flange and a cylindrical sieve mounted on said flange and surrounding the Wide end of said nozzle. 7

10. A steam trap comprising a casing having a steam inlet thereto and a tubular discharge for water of condensation therefrom, a valve body in the form of a sleeve screwing on said tubulardischarge, an inner flange on said valve body for normally engaging said tubular discharge and for closing the same, a continuously open conical nozzle forming a resistance in the path of flow of the fluid and converging in the direction of flow and located centrally onsaid flange, and a cylindrical sieve mounted on said flange and surrounding the wide end of said nozzle said sieve being held to rotate with said screwed sleeve.

ing in the direction of said flow,said nozzle being located centrally of said flange and a cylindrical sieve carried by said flange, to r0 tate with said threaded sleeve and surrounding the wide end of said nozzle, said sieve being located so that steam entering by the inlet sweeps tangentially over the outer cylindrical surface of the sieve.

12. A steam trap comprising acasing, a fluid inlet thereto, a fluid discharge therefrom, a blow-ofl' valve in the path of the fluid from said inlet to said discharge, a continuously open and downwardly converging nozzle in the said valve and forming a resistance to the flow of fluid through said trap when said'blow-ofl valve is closed and a sieve mounted over said nozzle and rotatable with said valve.

In testimony whereof I hereunto affix my signature.

FREDERIK BASENAU. 

